Apparatus and method for supporting a boom frame of a crop sprayer

ABSTRACT

A crop sprayer includes a chassis, and a lift frame secured to the chassis, the lift frame having a left boom support and a right boom support. The crop sprayer includes a boom frame having a left boom support contact member and a right boom support contact member, wherein the boom frame is movable between (i) a first vertical position relative to the lift frame, and (ii) a second vertical position relative to the lift frame, and wherein the second vertical position is located at a height vertically above the first vertical position. The crop sprayer further includes a lift cylinder operable to move the boom frame in relation to the lift frame between the first vertical position and the second vertical position. The left boom support, the right boom support, the left boom support contact member, and the right boom support contact member are each spaced apart from the lift cylinder. When the boom frame is located at the first vertical position (i) the left boom support contact member rests on the left boom support, and (ii) the right boom support contact member rests on the right boom support, whereby the boom frame is able to be supported and maintained at the first vertical position without assistance of the lift cylinder. A method of supporting a boom frame of a crop sprayer is also disclosed.

This application is a continuation of application Ser. No. 09/050,455,filed Mar. 30, 1998.

TECHNICAL FIELD OF THE INVENTION

The present invention relates generally to a crop sprayer, and moreparticularly to an apparatus and method for supporting a boom frame of acrop sprayer.

BACKGROUND OF THE INVENTION

A crop sprayer is used to distribute chemicals, such as herbicides,pesticides, and fertilizers, over crops in a field during a sprayingoperation. The chemicals are held in a storage tank prior to beingsprayed upon the field.

SUMMARY OF THE INVENTION

In accordance with a first embodiment of the present invention, there isprovided a crop sprayer which includes a chassis and a lift framesecured to the chassis, the lift frame having a boom support. The cropsprayer further includes a boom frame having a boom support contactmember, wherein the boom frame is movable between (i) a first verticalposition relative to the lift frame, and (ii) a second vertical positionrelative to the lift frame, and wherein the second vertical position islocated at a height vertically above the first vertical position. Inaddition, the crop sprayer includes a lift cylinder operable to move theboom frame in relation to the lift frame between the first verticalposition and the second vertical position. The boom support and the boomsupport contact member are each spaced apart from the lift cylinder. Theboom support contact member rests on the boom support when the boomframe is located at the first vertical position, whereby the boom frameis able to be supported and maintained at the first vertical positionwithout assistance of the lift cylinder.

In accordance with a second embodiment of the present invention there isprovided a method of supporting a boom frame of a crop sprayer, with theboom frame being movable between (i) a first vertical position relativeto a lift frame, and (ii) a second vertical position relative to thelift frame, and with (i) the boom frame having a boom support, and (ii)the lift frame having a boom support contact member. The method includesthe step of extending a lift cylinder so as to move the boom frame fromthe first vertical position to the second vertical position, wherein thesecond vertical position is located at a height vertically above thefirst vertical position. The method further includes the step ofretracting the lift cylinder so as to move the boom frame from thesecond vertical position to the first vertical after the extending step,wherein the boom support contact member is positioned in contact withthe boom support when the boom frame is located in the first verticalposition. In addition, the method includes the step of supporting theboom frame with the lift member by interaction of the boom support andthe boom support contact member after the retracting step, whereby theboom frame is able to be maintained at the first vertical positionwithout assistance of the lift cylinder.

In accordance with a third embodiment of the present invention there isprovided a crop sprayer which includes a chassis, and a lift framesecured to the chassis, the lift frame having a left boom support and aright boom support. The crop sprayer also includes a boom frame having aleft boom support contact member and a right boom support contactmember, wherein the boom frame is movable between (i) a first verticalposition relative to the lift frame, and (ii) a second vertical positionrelative to the lift frame, and wherein the second vertical position islocated at a height vertically above the first vertical position.Moreover, the crop sprayer includes a lift cylinder operable to move theboom frame in relation to the lift frame between the first verticalposition and the second vertical position. The left boom support, theright boom support, the left boom support contact member, and the rightboom support contact member are each spaced apart from the liftcylinder. When the boom frame is located at the first vertical position(i) the left boom support contact member rests on the left boom support,and (ii) the right boom support contact member rests on the right boomsupport, whereby the boom frame is able to be supported and maintainedat the first vertical position without assistance of the lift cylinder.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a crop sprayer which incorporates thefeatures of the present invention therein;

FIG. 2 is a schematic view of the crop sprayer of FIG. 1;

FIG. 3 is an enlarged side elevational view of the crop sprayer of FIG.1 showing the chemical receptacle in greater detail;

FIG. 4A is an enlarged and exploded view of the mounting bracket used tomount the nozzles on the crop sprayer of FIG. 1;

FIG. 4B is another enlarged and exploded view of the mounting bracket ofFIG. 4A, but showing an opposite side thereof;

FIG. 4C is a perspective view of the assembled mounting bracket of FIG.4C, note the mounting bracket is attached to the boom arm;

FIG. 5 is an enlarged perspective view of the front suspension of thecrop sprayer of FIG. 1, note that the engine cover (i.e. hood) and aportion of a front wheel have been removed for clarity of description;

FIG. 6A is a front elevational view of a lift frame and a boom frameviewed from the line 6A--6A of FIG. 7A, as viewed in the direction ofthe arrows;

FIG. 6B is a fragmentary front elevational view of the front boomsupport and the boom arm viewed from the line 6B--6B of FIG. 7A, asviewed in the direction of the arrows;

FIG. 7A is a fragmentary side elevational view of the chassis and boomarm of the crop sprayer of FIG. 1 with the boom arm shown positionedabove the front boom support, note that the cab and storage tank areshown in phantom and a tip portion of the boom arm has been omitted forclarity of description;

FIG. 7B is view similar to FIG. 7A, but showing the boom arm resting ona front boom support but positioned above the rear boom support; and

FIG. 7C is view similar to FIG. 7A, but showing the boom arm resting onboth the front boom support and the rear boom support.

BEST MODE FOR CARRYING OUT THE INVENTION

While the invention is susceptible to various modifications andalternative forms, a specific embodiment thereof has been shown by wayof example in the drawings and will herein be described in detail. Itshould be understood, however, that there is no intent to limit theinvention to the particular form disclosed, but on the contrary, theintention is to cover all modifications, equivalents, and alternativesfalling within the spirit and scope of the invention as defined by theappended claims.

Referring now to FIG. 1, there is shown a crop sprayer 10. The cropsprayer 10 includes a chassis 12. The chassis 12 is a support frame thatspans most of the length of the crop sprayer 10 and provides a structurefor mounting other components of the crop sprayer 10 thereon. The cropsprayer 10 includes a cab 11 mounted on the chassis 12. The cab 11houses an operator and a number of controls of the crop sprayer 10.

An engine 14 is mounted on a forward portion of the chassis 12 in frontof the cab 11. The engine 14 is a diesel engine which is commerciallyavailable from Cummins Engine Co. Inc., of Columbus, Ind. as model 4BT.

The chassis 12 is supported by a pair of rear wheels 16 and a pair offront wheels 18. The rear wheels 16 are driven by the engine 14 so as topropel the crop sprayer 10 in the general direction of arrows 20 and 22.In particular, the engine 14 generates mechanical energy which istransferred to the rear wheels 16 by a transmission (not shown), driveshaft (not shown), and rear differential (not shown). The front wheels18 are operable to steer the crop sprayer 10.

The crop sprayer 10 further includes a storage tank 24 which storesdiluted chemicals, such as herbicides, pesticides, and fertilizers to besprayed on a field. The storage tank 24 is mounted on the chassis 12,aft of the cab 11.

The crop sprayer 10 further includes a boom arm 25 which is operable todistribute the chemicals over a wide swath in a field. In particular,the diluted chemicals are distributed by a number of nozzles 38 (shownin FIG. 2) which are spaced along the boom arm 25 through which thediluted chemicals are sprayed through the nozzles 38 as the crop sprayer10 is propelled in the general direction of arrows 20 and 22.

Referring now to FIG. 2, there is shown a schematic of the crop sprayer10. The storage tank 24 is in fluid communication with a first sprayerconduit 26. The first sprayer conduit 26 is further in fluidcommunication with an inlet 28 of a sprayer pump 30. An outlet 32 of thesprayer pump 30 is in fluid communication with a second sprayer conduit34. The second sprayer conduit 34 is in fluid communication with a spraybar 36.

The sprayer pump 30 is powered by a hydraulic pressure source, such as ahydraulic pump 82. The hydraulic pump 82 draws low pressure hydraulicfluid from a hydraulic fluid sump 83. The hydraulic fluid is thencompressed and advanced from a high pressure outlet 85 of the hydraulicpump 82 as high pressure hydraulic fluid. A high pressure line 87 is influid communication with the high pressure outlet 85. The high pressurehydraulic fluid is then supplied to various systems of the crop sprayer10, such as the sprayer pump 30, via the high pressure line 87. Inparticular, the sprayer pump 30 receives high pressure hydraulic fluidfrom the high pressure line 87 via a hydraulic inlet 31. The highpressure hydraulic fluid powers the spray pump 30 thereby reducing thepressure of the hydraulic fluid. The reduced pressure hydraulic fluid isthen exhausted via a hydraulic outlet 33 and returned to the hydraulicsump 83.

When the sprayer pump 30 is actuated, diluted chemicals from the storagetank 24 are advanced from the storage tank 24 to the inlet 28 of thesprayer pump 30. The diluted chemicals are then advanced from the outlet32 of the sprayer pump 30 to the second sprayer conduit 34.

From the second sprayer conduit 34, the diluted chemicals are advancedto the spray bar 36. The spray bar 36 has the nozzles 38 spaced alongthe length thereof. The nozzles 38 allow the diluted chemicals to beadvanced from the spray bar 36 to the field which lies below the nozzles38.

Thus, actuation of the sprayer pump 30 advances diluted chemicals fromthe storage tank 24 to the field via a fluid path that includes thefirst sprayer conduit 26, the sprayer pump inlet 28, the sprayer pumpoutlet 32, the second sprayer conduit 34, the spray bar 36, and thenozzles 38.

The crop sprayer 10 further includes a chemical receptacle 40. Thechemical receptacle 40 is advantageously configured to receive andtemporarily hold concentrated chemicals such as herbicides, pesticides,and fertilizers therein. These chemicals are distributed as concentratedchemicals from the manufacturer in order to reduce the weight and bulkof the chemicals. The reduced weight and bulk decreases the cost oftransporting the chemicals from the manufacturing site to the field.However, the concentrated chemicals must be diluted prior to beingsprayed onto the field.

The chemical receptacle 40 is in fluid communication with a firstloading conduit 42. The first loading conduit 42 is further in fluidcommunication with an inlet 44 of an electric pump 46. An outlet 48 ofthe electric pump 46 is in fluid communication with a second loadingconduit 50. The second loading conduit 50 is in fluid communication withthe storage tank 24.

The electric pump 46 is an electrically powered centrifugal pump. Onecentrifugal pump which may be used with the present invention iscommercially available from Hypro Inc. of New Brighton, Minn. as modelnumber 9700B.

Activation of the electric pump 46 advances concentrated chemicals fromthe chemical receptacle 40 to the storage tank 24 via a fluid path thatincludes the first loading conduit 42, the electric pump inlet 44, theelectric pump outlet 48, and the second loading conduit 50.

The electric pump is electrically powered by a battery 52. Inparticular, a first actuation of a switch 54 electrically connects anode 56 of the battery 52 to a node 58 of the pump 46. Connecting thenode 56 to the node 58 allows current to flow from the battery 52, alonga line 60, and along a line 62 to the electric pump 46. The circuit iscompleted by a line 64 which connects a node 66 of the electric pump 46to a node 68 of the battery 52. Thus, the first actuation of switch 54activates the electric pump 46.

A second actuation of the switch 54 disconnects node 56 from node 58 andisolates the electric pump 46 from the battery 52. Thus, the secondactuation of switch 54 deactivates the electric pump 46.

The battery 52 is further electrically coupled to a number of componentsassociated with the engine 14. In particular, the engine 14 includes afuel injector 70 for pressurizing fuel prior to injecting the fuel intoa combustion chamber (not shown), an engine control module 72 forcontrolling various engine components such as the fuel injector 70, afuel pump 74 for advancing fuel from a fuel tank (not shown) to thecombustion chamber, and an alternator 76 which converts mechanicalenergy from the engine 14 to electrical energy which is used to chargethe battery 52. Each of these components is electrically coupled to thebattery 52.

The engine 14 further includes a crankshaft 80. The energy generated bythe combustion of fuel in the combustion chamber is converted intorotational energy of the crankshaft 80. The crankshaft 80 ismechanically coupled to the hydraulic pump 82. The hydraulic pump 82supplies pressurized hydraulic fluid to a number of systems on the cropsprayer 10. For example, pressurized hydraulic fluid is used tomanipulate the boom arm 26, steer the front wheels 18, and power thesprayer pump 30.

It should be appreciated that the engine 14 can either be in an off modeor a running mode. In the off mode, the engine 14 combusts no fuel inthe combustion chamber and produces no mechanical energy. In the runningmode, the engine 14 combusts fuel in the combustion chamber and producesmechanical energy in the form of rotational energy of the crankshaft 80.Due to the small volume of concentrated chemicals in the chemicalreceptacle 40, the electric pump 46 can be activated while the engine 14is in the off mode as well as the running mode. In particular, becausethe electric pump 46 draws power directly from the battery 52, theengine 14 does not have be in the running mode to power the electricpump 46. However, systems that are powered by pressurized hydraulicfluid provided by the hydraulic pump 82, such as the sprayer pump 30,only function when the engine 14 is in the running mode. Hence, tooperate such systems, the engine 14 must be in the running mode in orderto supply mechanical energy to the hydraulic pump 82 via the crankshaft80.

The crankshaft 80 is also mechanically coupled to the alternator 76. Thealternator 76 converts the rotational energy of the crankshaft 80 intoelectrical energy. This electrical energy is then used to recharge thebattery 52 when the engine 14 is in the running mode.

To operate the crop sprayer 10, the storage tank 24 is filled with aquantity of water. The concentrated chemicals in the form of aconcentrated chemical solution are then placed in the chemicalreceptacle 40. The switch 54 is then actuated a first time so toelectrically couple the electric pump 46 to the battery 52. Electricalcurrent from the battery 52 activates the electric pump 46 so as toadvance the concentrated chemicals from the chemical receptacle 40,through the first loading conduit 42, through the electric pump inlet44, through the electric pump outlet 48, through the second loadingconduit 50, and into the storage tank 24.

Once the concentrated chemicals have been advanced to the storage tank24, the concentrated chemicals and the water become commingled. Thecommingling of the concentrated chemicals and water forms a dilutedchemical solution in the storage tank 24.

After the concentrated chemicals have been advanced to the storage tank24, the switch 54 is actuated a second time. The second actuation of theswitch 54 deactivates the electric pump 46 so as to prevent furtheradvancement of the concentrated chemicals to the storage tank 24.

To advance the diluted chemicals to the field, the sprayer pump 30 isactuated. Since the sprayer pump 30 is powered by pressurized hydraulicfluid supplied by the hydraulic pump 82, the engine 14 must be in therunning mode. Once actuated, the sprayer pump 30 advances the dilutedchemicals from the storage tank 24 to the spray bar 36. From the spraybar 36, the diluted chemicals are advanced through the nozzles 38 ontothe field.

It should be appreciated that to spread the diluted chemicals over thefield, the crop sprayer 10 must be moving in the general direction ofarrows 20 or 22 of FIG. 1 while the diluted chemicals are advancedthrough the nozzles 38 onto the field. It should further be appreciatedthat the operator in the cab 11, controls the actuation of the sprayerpump 30 and the movement of the crop sprayer 10.

Pontoon Structures

Referring now to FIG. 3, there is shown an enlarged side elevationalview of the crop sprayer 10 of FIG. 1. The crop sprayer 10 includes apontoon structure 84. In particular, a frame 96 of the pontoon structure84 is secured to the chassis 12 of the crop sprayer 10. The pontoonstructure 84 includes of an upper surface 86 and a fairing or protectivecovering 88. The upper surface 86 can be used as a walking surface whichallows the operator to walk in the general directions of arrows 92 and94 on top of the pontoon structure 84.

The fairing 88 is operable to isolate any one of a number of componentsthat may be secured to the chassis 12 from physical contact with theoperator of the crop sprayer 10. These components may include a fueltank, a hydraulic fluid reservoir, or other items commonly mounted tothe chassis 12 of a crop sprayer 10. In addition, the fairing 88 isoperable to hide these components from the operator's view so as tocreate a more aesthetically pleasing appearance for the crop sprayer 10.

The chemical receptacle 40 is integrated into the pontoon structure 84.In particular, the upper surface 86 of the pontoon structure 84 includesa door 90. The door 90 is pivotally secured to the frame 96 of thepontoon structure 84 by a pair of hinges 98 such that the door 90 isfree to pivot relative to the frame 96 in the general directions ofarrows 99 and 100. The chemical receptacle 40 is supported by the frame96. In addition, the switch 54 is secured to the frame 96 proximate tothe chemical receptacle 40. It should be noted that the chemicalreceptacle 40 occupies a portion of the interior space defined by thepontoon structure 84.

In operation, when it is desirable to advance concentrated chemicalsfrom the chemical receptacle 40 to the storage tank 24, the door 90 isrotated relative to the frame 96 in the general direction of arrow 100to an open position, as shown in FIG. 3. The concentrated chemicals arepoured into the chemical receptacle 40. The pontoon structure 84 isadvantageously configured to allow the operator of the crop sprayer 10to pour the concentrated chemicals into the chemical receptacle 40 whenthe operator is standing on the ground.

To activate the electric motor 46, the switch 54 is actuated a firsttime by pressing the switch 54 in the general direction of arrow 101.The electric pump 46 then advances the concentrated chemicals from thechemical receptacle 40 to the storage tank 24 as described above. Todeactivate the electric motor 46, the switch 54 is actuated a secondtime by pressing the switch 54 in the general direction of arrow 101.Deactivating the electric pump 46 prevents the advancement ofconcentrated chemicals from the chemical receptacle 40 to the storagetank 24.

After the concentrated chemicals have been advanced to the storage tank24, the door 90 is pivoted relative to the frame 96 in the generaldirection of arrow 99 until the door 90 is positioned in the closedposition whereby the door 90 covers the opening of the chemicalreceptacle 40. In the closed position, the door 90 lies in the sameplane as the upper surface 86 thereby allowing the door 90 to be used asa walking surface. In addition, when the door 90 is in the closedposition, the door 90 prevents objects from entering the chemicalreceptacle 40. Furthermore, in the closed position, the door 90 preventsinadvertent actuation of the switch 54.

Spray Bar Mounting Brackets

Referring now to FIGS. 4A and 4B, there is shown a mounting bracket 102used to secure the spray bar 36 to the boom arm 25. The mountingbrackets 102 are positioned in an aligned orientation along the boom arm25 as shown in FIG. 1.

FIG. 4A shows the mounting bracket 102 as viewed from a position behindthe crop sprayer 10 looking in the general direction of arrow 20 ofFIG. 1. The spray bar 36 is secured to the mounting bracket 102 by apair of bolts 104, which are received through holes 106 defined in themounting bracket 102. The bolts 104 secure the nozzle 38 to the mountingbracket 102. In particular, the nozzle 38 includes a tip portion 37 anda base portion 39. To assemble the nozzle 38, the spray bar 36 isinterposed between the tip portion 37 and the base portion 39. The bolts104 are received through a respective hole 106 in the mounting bracket102, through a respective aperture 112 in the base portion 39, and intoa respective threaded aperture 114 in the tip portion 37. As the bolts104 are rotatably advanced in the general direction of arrow 108, thespray bar 36 is compressed between the base portion 39 and the tipportion 37 of the nozzle 38. As the spray bar 36 is compressed, anupwardly projecting annular member (not shown) of the tip portion 37punctures the spray bar 36 so as to place an outlet 116 of the nozzle 38in fluid communication with an interior passage 118 of the spray bar 36.When the spray pump 30 is actuated, the diluted chemicals are advancedfrom the storage tank 24 to the field via the interior passage 118 ofthe spray bar 36 and the outlet 116 of the nozzle 38. In addition,advancement of the bolts 104 in the general direction of arrow 108secures the spray bar 36 to the mounting bracket 102. It should beappreciated that FIG. 4A shows only one exemplary nozzle 38 of thenumber of nozzles 38 which are spaced along the mounting bracket 102.

FIG. 4B shows the mounting bracket 102 as viewed from a position infront of the crop sprayer looking in the general direction of arrow 22.After the spray bar 36 is secured to the mounting bracket 102 in themanner previously discussed, the mounting bracket 102 is secured to theboom arm 25. In particular, the mounting bracket 102 is secured to aboom arm member 120 by first plate 121 and a second plate 123. The firstplate 121 and second plate 123 are secured to the mounting bracket 102by a pair of bolts 124 that are received through a respective hole 128defined in the first plate 121 and a respective hole 129 defined in thesecond plate 123. The bolts 124 are further received through arespective hole 126 defined in the mounting bracket 102. The bolts 124are then threadingly engaged with a respective threaded nut 130. As thebolts 124 are advanced in the general direction of arrow 132, the firstplate 121 and the second plate 123 secure the mounting bracket 102 tothe boom arm member 120 of the boom arm 25.

It should be appreciated that the use of mounting brackets 102 providesprotection for the nozzles 38 and the spray bar 36 during operation ofthe crop sprayer 10.

Offset Frame

Referring now to FIG. 5, the crop sprayer 10 further includes an offsetframe 148 which is secured to the chassis 12 at a location forward ofthe engine 14. The offset frame 148 is positioned at a location higherin the general direction of arrow 150 than the portion of the chassis 12that supports the engine 14. A front suspension assembly 140 is mountedto the underside of the offset frame 148. The front suspension assembly140 includes a generally "A" shaped frame 152 pivotally coupled to theoffset frame 148. In particular, a pin 155 pivotally couples the frame152 to a bracket 154 mounted to an underside of the offset frame 148whereas a pin 157 pivotably couples the frame 152 to a front plate 156secured to a front of the offset frame 148. The pins 155 and 157 allowthe frame 152 to pivot relative the offset frame 148 in the generaldirections of arrows 158 and 160. A top surface 153 of the frame 152 islocated at a first vertical height above the ground 144. The bottomsurface 13 of the chassis 12 is located at a second vertical heightabove the ground. It should be appreciated that the first verticalheight is greater than the second vertical height. This feature providesfor enhanced ground (or crop) clearance 142 as will be discussed below.

The left side of the front suspension 140 further includes a suspensionarm 162 secured to the frame 152. An axle 164 is positioned at the lowerend of the arm 162, and a steering lever 168 is positioned at an upperend of the suspension arm 162. The axle 164 allows the wheel 18 torotate relative to the chassis 12 in the general direction of arrows 177and 179. A steering member 166 connects the steering lever 168 and theaxle 164. In particular, rotation of the steering lever 168 in thegeneral direction of arrow 170, causes the steering member 166 and theaxle 164 to rotate relative to the suspension arm 162 in the generaldirection of arrow 170. On the other hand, rotation of the steeringlever 168 in the general direction of arrow 172, causes the steeringmember 166 and the axle 164 to rotate relative to the suspension arm 162in the general direction of arrow 172.

A steering cylinder 174 is operative to rotate the steering lever 168 inthe general directions of arrows 170 and 172. The steering cylinder 174is powered by pressurized hydraulic fluid from the hydraulic pump 82(shown in FIG. 2). In particular, when a rod 175 of the steeringcylinder 172 is extended in the general direction of arrow 176, thesteering lever 168, and thus the axle 164, is rotated in the generaldirection of arrow 172. On the other hand, when a rod 175 of thesteering cylinder 172 is retracted in the general direction of arrow178, the steering lever 168, and thus the axle 164 is rotated in thegeneral direction of arrow 170.

It should be appreciated that the front suspension 140 further includesa suspension arm, axle, steering lever, steering member, and steeringcylinder attached to the right side of the frame 152 substantiallyidentical to the components attached to the left side of the frame 152.

The ground clearance 142 of the crop sprayer 10 is the distance betweenthe ground 144 and the lowest point 146 of the crop sprayer 10.Typically, the lowest point- of crop sprayers which have heretofore beendesigned is at the bottom of a frame analogous to the frame 152 of thecrop sprayer 10. An objective in the design of any crop sprayer is toincrease the ground clearance 142 so as to allow the crop sprayer 10 tomove through a field while minimizing damage to the crops. Adisadvantage of increasing the ground clearance 142 is that increasingthe ground clearance 142 usually raises the center of gravity of thecrop sprayer 10 which decreases the stability of the crop sprayer 10.

It should be appreciated that mounting the front suspension 140 to theoffset frame 148 allows the ground clearance 142 to be increased withoutincreasing the height of the engine 14, cab 11, storage tank 24, andother heavy components of the crop sprayer 10. Thus, the use of theoffset frame 148 allows the ground clearance 142 to be increased withoutsignificantly increasing the center of gravity of the crop sprayer 10.Hence, the crop sprayer 10 has the advantage of increased groundclearance 142 without the disadvantage of raising the center of gravityof the crop sprayer 10.

Rear Boom Support

Referring now to FIG. 6A, a lift frame 192 is secured to the chassis 12.A boom frame 188 is slidingly attached to the lift frame 192 such thatthe boom frame 188 is operable to slide up in the general direction ofarrow 180 relative to the lift frame 192, and down in the generaldirection of arrow 182 relative to the lift frame 192. A lift cylinder204 is interposed between a lower portion of the lift frame 192 and theboom frame 188. The lift cylinder 204 includes a head end 204HE and arod end 204RE (see FIG. 6A). Hydraulic pressure from the hydraulic pump82 (shown in FIG. 2) is supplied to the lift cylinder 204. As the liftcylinder 204 is extended, the boom frame 188 slides upwardly in thegeneral direction of arrow 180 relative to the lift frame 192. On theother hand, as the lift cylinder 204 is retracted, the boom frame 188slides downwardly in the general direction of arrow 182 relative to thelift frame 192.

The lift frame 192 includes a pair of rear boom supports 206 whichextend radially outward from the lift frame 192. Each of the rear boomsupports 206 is further supported by a support beam 208 which isinterposed between the rear boom support 206 and the chassis 12. Thesupport beam 208 provides additional structural support for loads thatare applied to the rear boom supports 206 in the general direction ofarrow 182.

Referring now to FIG. 6B, a front boom support 210 is secured to thechassis 12 of the crop sprayer 10. A plate 212 is secured to the upperportion of the front boom support 210. The front boom support 210 andthe plate 212 are advantageously configured to support a front portionof the boom arm 25 as shown in FIGS. 6B and 6C.

Referring to FIG. 7A, the boom arm 25 is pivotally secured to the boomframe 188 at a pivot joint 190. Note that a tip portion 186 (see FIG. 1)of the boom arm 25 is not shown in FIGS. 6A, 6B, and 6C for clarity ofdescription. The pivot joint 190 allows the boom arm 25 to pivotrelative to the boom frame 188 in the general direction of arrows 184and 185. A pivot cylinder 194 is operative to move the boom arm 25 inthe general direction of arrows 184 and 185 relative to the boom frame188. The pivot cylinder 194 includes a head end 194HE and a rod end194RE (see FIG. 7C). Hydraulic pressure from the hydraulic pump 82(shown in FIG. 2) is supplied to the pivot cylinder 194. In particular,as the pivot cylinder 194 is extended in the general direction of arrow200, the boom arm 25 is pivoted in the general direction of arrow 184relative to the boom frame 188. Conversely, as the pivot cylinder 194 isretracted in the general direction of arrow 201, the boom arm 25 ispivoted in the general direction of arrow 185 relative to the boom frame188. The cylinder 194 is attached to the boom frame 188 at a cylinderbracket 195. Since the cylinder brackets 195 at times contact the boomsupports 206, the cylinder brackets 195 may be referred to as boomsupport contact members.

The boom arm 25 is shown positioned in a retracted position in FIG. 7A.To move from the extended position (shown in FIG. 1) to the retractedposition (shown in FIG. 7A), the boom arm 25 is first raised in thegeneral direction of arrow 180, then pivoted in the general direction ofarrow 185. The lift cylinder 204 is extended to raise the boom arm 25 inthe general direction of arrow 180, and the pivot cylinder 194 isretracted to pivot the boom arm 25 in the general direction of arrow185.

The boom arm 25 is supported by the boom frame 188, which in turn issupported by the lift cylinder 204. The lift cylinder 204 supports theboom arm 25 with pressurized hydraulic fluid from the hydraulic pump 82.In particular, changes in the volume of hydraulic fluid contained in thelift cylinder 204 extends and retracts the lift cylinder 204 so as tomove the lift frame 188.

Referring now to FIG. 7B, to position the boom arm 25 on the front boomsupport 210, the boom arm 25 must be lowered in the general direction ofarrow 182. In particular, the lift cylinder 204 (shown in FIG. 6A) isretracted so as to lower the boom frame 188, which in turn lowers theboom arm 25. The lift cylinder 204 is retracted until the boom arm 25comes into contact with the plate 212 secured to the front boom support210. It should be appreciated that when the boom arm 25 is positioned inthe position shown in FIG. 7B, the boom arm 25 is partially supported bythe front boom support 210 and partially supported by the lift cylinder204.

Referring now to FIG. 7C, to support the boom arm 25 with the rear boomsupport 206, the lift cylinder 204 is retracted until the cylinderbracket 195 rests on the rear boom support 206. It should be appreciatedthat when the boom arm 25 is positioned in the position shown in FIG.7C, the boom arm 25 is supported by the front boom support 210 and therear boom support 206 which removes substantially all of the load of theboom arm 25 from the lift cylinder 204. Removing the load from the liftcylinder 204 allows the boom arm 25 to be supported without supplyingpressurized hydraulic fluid to the lift cylinder 204. Thus, the boom arm25 can be supported in the position shown in FIG. 7C when the engine 14is in the off mode.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, such illustration and description isto be considered as exemplary and not restrictive in character, it beingunderstood that only the preferred embodiment has been shown anddescribed and that all changes and modifications that come within thespirit of the invention are desired to be protected.

What is claimed is:
 1. A crop sprayer, comprising:a chassis; a liftframe secured to said chassis, said lift frame having a boom support; aboom frame having a boom support contact member, wherein said boom frameis movable between (i) a first vertical position relative to said liftframe, and (ii) a second vertical position relative to said lift frame,and wherein said second vertical position is located at a heightvertically above said first vertical position; and a lift cylinderoperable to move said boom frame in relation to said lift frame betweensaid first vertical position and said second vertical position, whereinsaid boom support and said boom support contact member are each spacedapart from said lift cylinder, and wherein said boom support contactmember rests on said boom support when said boom frame is located atsaid first vertical position, whereby said boom frame is able to besupported and maintained at said first vertical position withoutassistance of said lift cylinder.
 2. The crop sprayer of claim 1,wherein said boom frame further includes a support beam interposedbetween said chassis and said boom support, whereby said support beamprovides additional support for loads applied to said boom support. 3.The crop sprayer of claim 1, wherein:said lift cylinder includes a headend and a rod end, said head end of said lift cylinder is secured tosaid lift frame, and said rod end of said lift cylinder is secured tosaid boom frame.
 4. The crop sprayer of claim 1, further comprising apivot cylinder adapted to move a boom arm in relation to said boomframe, wherein:said boom support contact member includes a cylinderbracket, and said cylinder bracket rests on said boom support when saidboom frame is located at said first vertical position.
 5. The cropsprayer of claim 4, wherein:said pivot cylinder includes a head end anda rod end, and said head end of said pivot cylinder is secured to saidcylinder bracket.
 6. The crop sprayer of claim 1, wherein:said boomsupport includes a horizontally oriented member, and said boom supportcontact member contacts a top surface of said horizontally orientedmember when said boom frame is located at said first vertical position.7. The crop sprayer of claim 6, wherein said boom support contact memberis spaced apart from said top surface of said horizontally orientedmember when said boom frame is located at said second vertical position.8. A method of supporting a boom frame of a crop sprayer, with the boomframe being movable between (i) a first vertical position relative to alift frame, and (ii) a second vertical position relative to the liftframe, and with (i) the boom frame having a boom support, and (ii) thelift frame having a boom support contact member, comprising the stepsof:extending a lift cylinder so as to move said boom frame from thefirst vertical position to the second vertical position, wherein thesecond vertical position is located at a height vertically above thefirst vertical position; retracting said lift cylinder so as to move theboom frame from the second vertical position to the first vertical afterthe extending step, wherein the boom support contact member ispositioned in contact with the boom support when said boom frame islocated in the first vertical position; and supporting the boom framewith the lift member by interaction of the boom support and the boomsupport contact member after the retracting step, whereby the boom frameis able to be maintained at said first vertical position withoutassistance of said lift cylinder.
 9. The method of claim 8, wherein saidboom support and said boom support contact member are each spaced apartfrom said lift cylinder.
 10. The method of claim 8, wherein said boomframe further includes a support beam interposed between said chassisand said boom support, whereby said support beam provides additionalsupport for loads applied to said boom support.
 11. The method of claim8, further comprising a pivot cylinder adapted to move a boom arm inrelation to said boom frame, wherein:said boom support contact memberincludes a cylinder bracket, and said cylinder bracket rests on saidboom support when said boom frame is located at said first verticalposition.
 12. The method of claim 8, wherein:said boom support includesa horizontally oriented member, and said boom support contact membercontacts a top surface of said horizontally oriented member when saidboom frame is located at said first vertical position.
 13. The method ofclaim 12, wherein said boom support contact member is spaced apart fromsaid top surface of said horizontally oriented member when said boomframe is located at said second vertical position.
 14. A crop sprayer,comprising:a chassis; a lift frame secured to said chassis, said liftframe having a left boom support and a right boom support; a boom framehaving a left boom support contact member and a right boom supportcontact member, wherein said boom frame is movable between (i) a firstvertical position relative to said lift frame, and (ii) a secondvertical position relative to said lift frame, and wherein said secondvertical position is located at a height vertically above said firstvertical position; and a lift cylinder operable to move said boom framein relation to said lift frame between said first vertical position andsaid second vertical position, wherein said left boom support, saidright boom support, said left boom support contact member, and saidright boom support contact member are each spaced apart from said liftcylinder, and wherein when said boom frame is located at said firstvertical position (i) said left boom support contact member rests onsaid left boom support, and (ii) said right boom support contact memberrests on said right boom support, whereby said boom frame is able to besupported and maintained at said first vertical position withoutassistance of said lift cylinder.
 15. The crop sprayer of claim 14,wherein said boom frame further includes (i) a first support beaminterposed between said chassis and said first boom support, and (ii) asecond support beam interposed between said chassis and said second boomsupport, whereby (i) said first support beam provides additional supportfor loads applied to said first boom support, and (ii) said secondsupport beam provides additional support for loads applied to saidsecond boom support.
 16. The crop sprayer of claim 14, wherein:said liftcylinder includes a head end and a rod end, said head end of said liftcylinder is secured to said lift frame, and said rod end of said liftcylinder is secured to said boom frame.
 17. The crop sprayer of claim14, further comprising (i) a first pivot cylinder adapted to move afirst boom arm in relation to said boom frame, and (ii) a second pivotcylinder adapted to move a second boom arm in relation to said boomframe, wherein:said first boom support contact member includes a firstcylinder bracket, said first cylinder bracket rests on said first boomsupport when said boom frame is located at said first vertical position;said second boom support contact member includes a second cylinderbracket, and said second cylinder bracket rests on said second boomsupport when said boom frame is located at said second verticalposition.
 18. The crop sprayer of claim 14, wherein:said first boomsupport includes a first horizontally oriented member, said first boomsupport contact member contacts a first top surface of said firsthorizontally oriented member when said boom frame is located at saidfirst vertical position, said second boom support includes a secondhorizontally oriented member, and said second boom support contactmember contacts a second top surface of said second horizontallyoriented member when said boom frame is located at said first verticalposition.
 19. The crop sprayer of claim 14, wherein:said first boomsupport contact member is spaced apart from said first top surface ofsaid first horizontally oriented member when said boom frame is locatedat said second vertical position, and said second boom support contactmember is spaced apart from said second top surface of said secondhorizontally oriented member when said boom frame is located at saidsecond vertical position.